扫描电镜能谱仪测定不锈钢中镍含量测量结果的不确定度评定

Uncertainty evaluation on measurement result of nickel content in stainless steel by scanning electron microscope-energy dispersive spectrometry

为了解扫描电镜能谱仪定量分析结果的准确度,采用扫描电镜能谱仪对SUS-101g不锈钢中镍含量进行定量分析,对影响定量分析结果的不确定度分量包括重复性测定、修正方法、标准物质、实验室环境及设备校准证书等进行逐一讨论,并对各影响因素的不确定度分量进行计算和合成,计算扩展不确定度。测量过程执行标准GB/T 17359—2012《微束分析能谱法定量分析》。测量不确定度的评定结果表明:影响不确定度的来源主要有重复性测定、修正方法和设备校准证书3个方面,而标准物质和实验室环境的影响根据实际情况可以忽略。不确定度报告可表示为:测定结果镍质量分数为9.92%,扩展不确定度U=0.74%,取包含因子k=1.96。

In order to understand the accuracy of the quantitative analysis results by scanning electron microscope(SEM)-energy dispersive spectrometry(EDS),the nickel content in SUS-101g stainless steel was quantitatively determined by SEM-EDS.The uncertainty components that affected the quantitative results were discussed separately including as repeatability measurement,correction methods,certified reference materials,laboratory environment and equipment calibration certificates.The uncertainty components of each influencing factor were calculated and synthesized to obtain the expanded uncertainty.The whole measurement process was conducted according to the standard method,i.e.,GB/T 17359-2012 Microbeam analysis-Quantitative analysis by energy dispersive spectrometry.The evaluation results of measurement uncertainty showed that the source of uncertainty mainly included measurement repeatability,correction methods and equipment calibration certificates,while the influence of certified reference materials and laboratory environment could be ignored according to the actual situation.The uncertainty report could be expressed as:the measurement result of nickel content was 9.92%in mass fraction,and the expanded uncertainty was U=0.74%with coverage factor of k=1.96.